A mother's high blood pressure during pregnancy may affect her child's brain power throughout its life, the American Academy of Neurology journal suggests. About 400 men had their cognitive ability tested at the age of 20 and then again at the average age of 69. Those whose mothers had hypertension when pregnant scored lower marks at each age and also showed greater score decline over the decades. Hypertension may alter conditions in the womb which impairs foetal growth.